Water Power.
At the dam on the Ohinemuri river the summer flow is 25 sluice heads (cubic feet per second) and provides 320 h. p. by means of a 10 foot 6 inch pelton wheel. The pipe line is 1,800 feet long and 4 foot in diameter and the fall 80 feet. The dam in the Waitawheta gorge has a summer flow of 21.3 sluice heads and supplies water to a 100 h. p. Victor turbine which drives the lighting dynamos, about 46 h.p.
Water Supply.
The main from this dam also supplies water to the mill, a feed pump, capable of dealing with 16,000 gallons per hour, forcing it to the two supply tanks at the top of the mill. The total water used is about 9 tons per ton of ore crushed.
Steam Power.
There are four B. & W. boilers with 1,619 square feet of heating surface and fitted with chain-grate mechanical stokers. Steam from these boilers is supplied to the mill engine by a pipe line about 660 feet long. This engine is a compound-tandem Corliss engine of 560 h. p. by Messrs Fraser & Chalmers. The cylinders are 18 inches and 34 inches in diameter with 42 inch stroke. It runs at 72 r. p. m. and drives the main shaft by 12 ropes 2 1/8th inches in diameter.
Compressed Air.
The B. & W. boilers also supply steam to a Riedler air-compressor having a rated capacity of 3,100 cubic feet of free air p. m., and the blow-off valve of the receiver is set at 100lb. per square inch. An Ingersoll Rand compressor of a capacity of 3,700 cubic feet p. m., has been ordered and will be installed alongside it. The power from the Ohinemuri dam is utilized to drive an Ingersoll Rand compressor giving 1,250 cubic feet free air p. m. at 90lb. pressure and also a Union Iron Works Co machine giving 600 cubic feet free air p.m. at 40lb.